<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Css引入方式</title>

    <style>
        h2 {
            color: #ff00f2;
            background: #f7ffc4;
            width: 110px;
            height: 40px;
        }
    </style>
  <link rel="stylesheet" href="my.css">



</head>
<body>
<h1 style="color: red;background: aquamarine;width: auto;height: auto">内联样式1</h1>
<h1 id="n2">内联样式2</h1>
<h2>内部样式1</h2>
<h2>内部样式2</h2>
<h3>外部样式1</h3>
<h3>外部样式2</h3>
</body>
</html>